Dental drill and handpiece for same



Sept. 25, 1951 G. E. BJORKLUND DENTAL DRILL AND HANDPIECE FDR sAMD FiledAug. e, 1947 IN V EN TOR. GUSTAF ERIK BJORKLUND WMM ATTORNEY PatentedSept. 25, 1951 '2,568,408 I I I.: "DENTALDRrLn-AND HANDPIECEFOR SAMEGustar Eik-'Bjrklund, .Stoekholnnfl Sweden Application August 6,1947;."Ser'ial'Nof7l66595 InSweden August12f194'6 :s Claims. (C1.`279;.51) 1 l This invention relatesto dental drills and handpiecestherefor-and to means for .securing y:suclraldrll in operativepo'sition-withinthe -handin taper-eoecasioned hyl thefcomp'arativelyslight yfdim'ensien ofthe v diilland1-also :because .the :drills "wereto'o fr'agile to .withstand4 the repeated blows necessary iorzl'oosening.

.lt isia'nobject .ef the .present :invention to provvide )mechanicalmeans within "fthe han'dpece fdesigne'd itc .cooperate with theYusual'.tap'ered Iloca-ring .to 'providel axially' .':directed force for'fsec'uringaia' drill.: in position.. .By :means .of an arrangement ofithischaracterthe vtapernof .the 4rillllanl bearing within which :itseatswmay `be increase'd; to an extent .wherexno mechanical -blcw Y isrequired forthelocsening .and 'removal-thereof.

.lf desired vthe handpiece illustrated.- and -dev;s'cri`oediherein #mayThe designed. to accommodate the novel drill described and claimed inaqzxplimantsfcopending'application, SerialNo. 7663594 Another Ynovelhandpiecefdrill assembly 'has abeen` disclosed in 'applicantscapendingiapplcaton,Serial No. 766,596'lednAugustid 1947, now:EatentfNumberiZd-'lg' issued May 1.6f1950gfa'1so vnesigned.to.accommodate this :novel =dri1l fas well 'fasiotnerxeommerciallyavailable andfoomparable 'drills Further objects andiadvantages:ofthe-invention will be apparent from the followingdescription`1taken 'in conjunction with the accompanying drawing,wherein:

There is illustrated in the single figure of the accompanying Adrawing a=longitudinal-sectional view through a handpiece constructed finaccor'dance withrthe present `invention-and having a drill positionedtherein.

As shown in the drawing; y'thevdrill I "includes the usual abrad-ing -orcutting extremity 13 and faconical or tapered 'sha-nk portion 2 adaptedto 1loe 'seated within a complementary bearing or socket in a chuck I0.'An annular groove 4 is provided at the end of the tapered shank remotefrom the cutting extremity forming a flange or shoulder by means ofwhich the drill is retained infthe 'chuck as will iffully fdescribe'd.-

Diametrically opposed vprojections lor ilugsi-i lare qarovide'd,substantiallyadjacent to y:tuez-g'.reat- -est -rfdiameter fof thedrillf7 "a'dapted'ito fen-'gage Within fopposed slots-@Ill "formed atwthe* outer zexstrerrityroi -the chuck I'Il. Free"rotation6f :the

the hereinafter "more 'drill AWithin the vchuck is `thus prevented Thehandpiece '8 --o'f this invention 'includesvfa, Vconvenientfingering-aging portion and i is #prolvided.' "with "Vartubula'r bearingmember .for .s'leeve -9 1which extends:ftherebeyondfiand the=chuckYII-II includes a rotatable v'sleeve-likespindle' 'Iiwhich 'isjournalled Within this :bearing-member. To prevent .'chip's 'or votherfabrasive #matter :from

#entering lthe handpiecefth'e chuck is groove'd to provide vanAanular-iangefI2 :closely ada'centfto thepoint where thef.-rotatablefspindle 1 enters the bearing sleeve 9 of the handpiece..-x-This:structure @isfof particular iadvantagefduring vsuch `.times asftheAdrill-fis used 1in.arsemi-vertical :position Where `chipssforfothermatter ymight-vfallzdown or @tend tofcling tothe outer sur-facetoffthechuck, such matter being' discharged fby centrifugal force inadirectiontangential to the circumference-'of -thev flange I2 and eprevented -fromWorking into the frnechan-ismnf therhandpiece thus- `obviating anynecessity ,forfrequentv disassembly `andfcleaning.V

Inorder fgto Asecurely Iretain thefconical shank 2 of, the drillyvvi-th-ii-frthe .tapered )socket Yof the chuck IIJ which vvformspar-.tof the rotatable spindle,i.the'handpiece f 8-is :provided with anaxially `reciprocablesleeve I4 terminating in -a plurality `of spr-ingngers I6 lhaving ysubstantially :hook

shapedrextremities II- adapted to enga-gewithin theannular-groove 4behind the flange' on the yd-rilllz; The sleeve M is fxedlysecured as-by :a pin or-theflike I5 upon yan yaxially displaceable drive Vshaft:|713 suitably amounted within thehand- `piecefmr longitudinalfreciprocation.

flromsther yforegoing it will be readily 'understood 'that -whentheconicalwshankvZ of the drill-,is fseatedein thefchuck 'I Il, thefsleevel4 'may bev-moved 'axially in a direction away -from the "drill, thusidrawing the? drill I" tightly into the chucky'Dearingi'randfrmaintaining 'engagement of "the 'lugs When Yit isdesired: to vretinov'e theldrillro'm thechuck it is `o`nly .necessary tomove the sleeve f4 toward Ythe chuck I0, fat

cam surface I8 provided on the inner extremity of the chuck, within thespindle 1, and will be spread apart radially, thus releasing the ange 5and permitting ready withdrawal of the dril from the chuck.

The handpiece '8 is threadedly or otherwise secured to a tubular casingI9 and the shaft I3 extends into this casing and carries a couplingmember adapted for engagement with the usual driving mechanism (notshown). Preferably this coupling member surrounds the extremity of theshaft, a pin or the like 2| being provided to insure operativeengagement between shaft and coupling.

Any desired means may be provided for axially l displacing the shaft I3within the handpiece 8,

tion without departing from the spirit and scope thereof and thereforethe invention is not limited by that which is illustrated in the drawingand described in the specification but only as indicated in the appendedclaims.

What I claim is:

1. A handpiece for a dental drill including a spindle rotatablymountedtherein and extending substantially therebeyond, a tapered drillreceiving socket in said spindle and a diametrically disposed slot inthe outer end thereof for interengagement with projecting lugs upon adental a preferred embodiment thereof comprising opcured thereto by anysuitable means such as a pin 26. The spindle I is provided with aslightly enlarged axial bore adapted to receive the extremity of thebushing and a coil spring 2'I is positioned within this bore insurrounding relationship' to the shaft I3. Normally this coil springurges the entire shaft assembly including the gripping fingers I6, thesleeve 2'2, and ring 24, in a direction away from the chuck I0.lifotative movement is imparted to the spindle 1 through the pin 26, theextremities of which project into opposed longitudinal slotsappropriately positioned in the inner extremity of the spindle.

` It will thus be apparent that an axial force is exerted upon the drillI through the spring 21, tending to seat the drill more securely within-the tapered bearing in the chuck. Advancement of the ring 2l will movethe sleeve 22, bushing 25 and shaft I3, compressing the spring 21 andforcing the claws I'I against the cam surface I8. The hooked extremitiesor claws will thus be spread apart, releasing the flange 5 and freeinglthe drill, which may `then be pushed or ejected from theY socket, areduced upper ,extremity 28 on the shaft I3 being provided to accomplishthis result. The ring 24, uponV release, will be returned to normalposition by the spring 21,A

When it is desired to insert another drill, the conical portion thereofis inserted within the tapered bearing of the chuck I0. The ring 24 isthen advanced, carrying the shaft I3 forward so that the claws I'I ofthe lingers I6 ride over the nange 5 on the adjacent extremity of thedrill and drop into the annular groove l.

There has thus been provided a drill and straight handpiece assembly soconstructed as to efficiently receive and rotate relatively short drillsof a character normally employed in an angular handpiece or one whichcarries a drill disposed -in angular relationship. The extension of thespindle beyond the finger engaging portion of the handpiece enablestheoperator to obtain maximum reach when the device is in use and permitsready removal and insertion of drills.

It will be obvious to those skilled in the art that various changes maybe made in the invendrill, an axially reciprocable sleeve Within saidspindle, hooked fingers on said sleeve adapted to engage in an annulargroove onV the inner end of the drill whereby said drill may be drawninto and retained in said socket, a second axially displaceable sleevewithin said handpiece, a drive shaft journalled within said secondsleeve and displaceable therewith, said drive shaft extending into saidfirst mentioned sleeve and being fixedly secured thereto, a coil springsurrounding the shaft and normally urging said shaft and second sleeveaway from the inner extremity of the drill, reciprocable means carriedupon the handpiece exteriorly thereof adapted to displace said secondsleeve and shaft to release the hooked fingers, a reduced upperextremity upon said shaft adapted to eject the drill when the hookedfingers are disengaged therefrom, and a driving connection between saidshaft and spindle.

2. A handpiece for a dental drill including aV spindle rotatably mountedtherein and provided with a tapered chuck adapted to receive the conicalshank of a drill, an axially displaceable sleeve reciprocable withinsaid handpiece, a drive shaft journalled within said sleeve and axiallydisplaceable therewith, hooked fingers on said shaft adapted to engagethe inner extremity of the drill whereby said drill may be drawn intoand retained in said chuck, a coil spring surrounding the shaft andnormally urging said shaft and sleeve away from the inner extremity ofthe drill, reciprocable means carried upon the handpiece exteriorlythereof adapted to displace said sleeve and said shaft to release thehooked fin- -gers and permit removal of the drill, and a drivingconnection between said shaft and spindle.

3. A handpiece for a dental drill including a spindle rotatably mountedtherein and provided with a tapered chuck adapted to receive the conicalshank of a drill, an axially displaceable GUSTAF ERIK BJRKLUND.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 213,167 Brown Mar. 11, 1879583,625 Lusby June 1, 1897 Andresen Aug. 1'7, 1926

